Length adjuster for slotted boom



Jan. 21, 1964 E. BRADLEY 1 LENGTH ADJUSTER FOR SLOTTED BOOM Filed April 6, 1962 2 Sheets-Sheet l INVENTOR. EDWARD L. BRADLEY Jan. 21, 1964 E. L. BRADLEY 3,118,415

LENGTH ADJUSTER FOR SLOTTED BOOM Filed April 6, 1962 2 Sheets-Sheet 2 120 n2 zoo I L |J 4 INVENTOR. EDWARD L. BRADLEY United States Patent 3,118,415 LENGTH ADJUSTER FOR SLOTTED BOOM Edward L. Bradley, 3552 Dodge St., Dmaha, Nebr. Filed Apr. 6, 1962, Ser. No. 185,706 2 Claims. (Cl. 114-98) This invention relates to devices for adjusting the shape of the sail of sail boats and more particularly it is an object of this invention to provide an adjuster for adjusting the tension of the sail along the boom.

More particularly it is an object of this invention to provide a boom extension mounted on a boom and movable into selectively chosen positions so that the distance from the forward end of the extension to the rearward end of the boom can be made to be a greater distance for stretching the foot of a sail for flattening the sail in high wind, and can be made a lesser distance for slackening the foot of the sail to allow the sail to have a greater curvature in lighter wind.

A further objective is to provide a sail adjuster as described which can be adjusted while the boat is in operation and particularly during racing.

Still another objective is to provide an adjuster as described which can be adjusted by simple movements of the crank.

Other and further objects and advantages of the present invention will be apparent from the following detailed description, drawings and claims, the scope of the invention not being limited to the drawings themselves as the drawings are only for the purpose of illustrating a way in which the principles of this invenion can be applied.

Other embodiments of the invention utilizing the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

in the drawings:

FIGURE 1 is a side elevation of a mast, boom, and sail with the adjuster attached, portions of the mast and sail being broken away, a portion of the boom also being broken away to show a slot.

FIGURE 2 is a detail showing the adjuster and asso ciated parts together with broken away portions of a mast, sail, and boom.

FIGURE 3 is a top plan view of the sail adjuster and associated parts, including broken away portions of mast and boom.

FEGURE 4 is a sectional view taken along the line 4-4 of FIGURE 3, the line 44 having an offset portion in the middle.

Referring to the drawings for a more particular desoription and to- FIGURE 1, a sailboat mast is there shown at 15?, the sail is shown at 12 and a boom at 14.

As best seen in FIGURE 2, a boom has a portion 16 along its upper side which has a conventional bolt-rope slot 17, best seen in FIGURE therethrough, not shown here, for receiving what is called a bolt-rope 21 which extends along the lower side or foot 24 of the sail. The bolt-rope 2% also has a vertical portion 2-2r which extends into a section 24 of the mast pen, the section 24 being similarly slotted, as is not shown.

As is conventional, the sail 12 has the grommet 30 in its forward lower corner for receiving a pin 32 which secures the sail to a clevis 34 which extends upwardly from a mounting 4d secured by post 42 and a nut 44 to a member 46 which latter is fixed to a track 50 received in a track holder 61? which latter is secured to the mast 111 by suitable means such as screws 64.

A connection member 70 extends rearwardly from the mounting 4d and has a bolt 72 extending through it for attaching a U-shaped fitting 8i pivotally to the member 3,118,415 Patented Jan. 21, 1964 70 whereby an elongated boom extension 84 attached to the U-shaped member can swing upwardly and downwardly with respect to the mast 10 about the bolt 72.

The boom extension 84 is preferably a threaded shaft and is loosely received in a bore extending horizontally through a boom extension receiving block 94.

The block 94 is received in a substantially U-shaped block mounting member which latter is fixed to the block 94 by screws 110.

The U-shaped member 100 wraps around the sides and the forward end of the block 94 and has side portions 112 which extend rearwardly along both sides of the forward end of the boom 14, the portions 112 being secured to the boom 14 by any suitable means such as bolts 1 20.

It is preferred that the side portions 112 of the block receiving member 1011 have outwardly oifset portions for receiving therein certain mechanisms now to be described.

A driven gear is threadedly and rotatably received on to the extension 1'34 and a driving gear is disposed in mesh with the driven gear 140 and is mounted on a shaft which latter is rotatably received in a bore 162 in the block 94 and also in a recess 164 in the forward end of the block 94.

The block 94 has an opening extending horizontally therethrough for receiving the gears 140 and 150 and the opening 162 is disposed on the lower side of the opening 170 whereas the recess 164 is disposed on an upper forward side of the opening 170 from the gear 150.

The gear 150 is fixed to the shaft 160 by a pin 174.

A crank handle fixed to the shaft 160 can be used to rotate the gears 140 and 150.

While the sailboat is being raced, either the crew or the skipper can usually reach the crank handle 11% for quickly rotating the gears 140 and 150 to cause the distance from the forward end of the extension 84 to the rearward end of boom 14 to be greater or lesser whereby upon a sudden increase or decrease in wind velocity, the effective shape of the sail can be made to be optimum.

It will be understood that some means, not shown, is used to fix the rearward end of the boom to the rearward end of the sail, as is conventional.

The invention can be understood best in terms of a new terminology different in some extent from the conventional terminology of this art. For example, a composite boom generally indicated at 300 is shown in the drawings having a forward end section generally indicated at 310 and a remainder or rearward end section generally indicated at 312. The remainder section 3 12 can be defined as that part of the boom 300' to which the side portions 112 are attached. The remainder section of the boom is, therefore, generally behind the adjusting assembly 310.

The adjusting assembly 310 itself comprises the boom extension 84 elongated in a direction parallel to the composite boom 360. The composite boom 300 extends approximately horizontally rearwardly of the mast 10.

The boom extension '84 forms a first main part of the adjusting assembly 3 10. Mounting means 320 forms a second main part of the adjusting assembly 310, such mounting means comprising all parts of the adjusting assembly 310 which are disposed between the forward end of the boom extension 84 and the remainder 312 of the composite boom.

Thus the mounting means has for some of its parts the side members 112, bolts 1-20, gears 140 and 150, and crank 180.

The mounting means 320 thus defined is movably attached to and disposed in lapping relationship with the rearward part of said boom extension for the expansion and contraction of the length of the adjusting assembly 310 in a direction parallel to the composite boom 300.

The non-lapping or forward part of the boom extension 84 projects forwardly from the mounting means 320, as seen in FIGURE 2, is attached to the mast as above described.

In operation, the movable attachment of the mounting means 320 with the extension 84 permits selective adjustment of the position of the forward end of the remainder 312 of the boom with respect to the mast 10, for stretching and slackening the foot of the sail to provide lesser and greater sail curvature as above described.

From the foregoing description, it is thought to be obvious that a sail shape adjuster constructed in accordance with my invention is particularly well adapted for use, by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention can be changed and modified without departing from the principles and spirit thereof, and for this reason, I do not wish to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice, except as claimed.

I claim:

1. A sail shape adjuster for attachment to the forward end of a boom of a sail boat comprising: a boom exten sion elongated in a direction parallel to the boom and anchored to the mast, mounting means attached to said boom and movably receiving said boom extension for movement of said extension forwardly and rearwardly with respect to the forward end of said boom for permitting selective adjustment of the position of the forward end of said extension, whereby the distance from the forward end of said extension to the rearward end of said boom can be made to be a greater distance for stretching the foot of a sail fixed to the rearward end of said boom for flattening the sail in high winds and can be made to be a lesser distance for slackening the foot of said sail to allow the sail to have a greater curvature in lighter winds, and means attached to said mounting means and operatively connected to said extension for adjusting the position of the forward end of said extension forwardly and rearwardly with respect to the forward end of said boom and '4 for holding said extension in a desired position of adjustment.

2. In combination: a sail boat having a mast, a composite boom extending approximately horizontally rearwardly from said mast, said composite boom comprising: a boom lentgh adjusting assembly forming a forward end section of said composite boom, the remainder of said boom being disposed generally behind said adjusting assembly, the remainder of said boom having an upwardly opening lengthwise slot therein for receiving the bolt-rope of a sail, said assembly comprising: a boom extension elongated in a direction parallel to said boom and forming a first main part of said assembly, mounting means forming a second main part of said assembly, means attaehing said parts of said assembly respectively to said mast and to said remainder of said boom, said mounting means being movably attached to and lapping part of said boom extension for expansion and contraction of the length of said assembly in a direction parallel to said boom, said boom extension having a non-lapping part projecting from said mounting means, said movable attachment of said mounting means and extension permitting selective adjustment of the position of the forward end of said remainder of said boom with respect to said mast for stretching the foot of a sail fixed to the rearward end of said boom for flattening the sail in high winds and for slackening the foot of said sail to allow the sail to have a greater curvature in lighter winds, and means attached to said mounting means and operatively connected to said extension for adjusting the length of said composite boom and for holding said extension in a desired position of adjustment with respect to said mounting means.

References Cited in the file of this patent UNITED STATES PATENTS 435,926 Frostad Sept. 9, i390 1,295,357 Nikonow Feb. 25, 1919 1,650,759 Larsen Nov. 29, 1927 FOREIGN PATENTS 5,3 2 Great Britain 1897 

1. A SAIL SHAPE ADJUSTER FOR ATTACHMENT TO THE FORWARD END OF A BOOM OF A SAIL BOAT COMPRISING: A BOOM EXTENSION ELONGATED IN A DIRECTION PARALLEL TO THE BOOM AND ANCHORED TO THE MAST, MOUNTING MEANS ATTACHED TO SAID BOOM AND MOVABLY RECEIVING SAID BOOM EXTENSION FOR MOVEMENT OF SAID EXTENSION FORWARDLY AND REARWARDLY WITH RESPECT TO THE FORWARD END OF SAID BOOM FOR PERMITTING SELECTIVE ADJUSTMENT OF THE POSITION OF THE FORWARD END OF SAID EXTENSION, WHEREBY THE DISTANCE FROM THE FORWARD END OF SAID EXTENSION TO THE REARWARD END OF SAID BOOM CAN BE MADE TO BE A GREATER DISTANCE FOR STRETCHING THE FOOT OF A SAIL FIXED TO THE REARWARD END OF SAID BOOM FOR FLATTENING THE SAIL IN HIGH WINDS AND CAN BE MADE TO BE A LESSER DISTANCE FOR SLACKENING THE FOOT OF SAID SAIL TO ALLOW THE SAIL TO HAVE A GREATER CURVATURE IN LIGHTER WINDS, AND MEANS ATTACHED TO SAID MOUNTING MEANS AND OPERATIVELY CONNECTED TO SAID EXTENSION FOR ADJUSTING THE POSITION OF THE FORWARD END OF SAID EXTENSION FORWARDLY AND REARWARDLY WITH RESPECT TO THE FORWARD END OF SAID BOOM AND FOR HOLDING SAID EXTENSION IN A DESIRED POSITION OF ADJUSTMENT. 